 |
 |
32 of 35 |  |
 |
 |
Road check the vehicle, if possible,
before
making any adjustments on the carburetor
to im
prove performance. Dragging brakes,
poor wheel
alignment, low tire pressure, and
other causes of
undue friction tend to retard engine
performance.
Evidence of leakage or dents in
the exhaust system
can cause trouble. Check the color
of the exhaust
for indications of an over-rich
mixture, for ex
cessive oil consumption and compression
loss.
A rough running engine coupled with
a strong odor
of gasoline may resultfrom aflooding
carburetor.
Improper engine temperature should
be corrected.
Many faults may be detected by a
visual inspection
of the engine in operation. Remedy
loose or dis
connected wiring, leaking fuel and
water con
nections, possible short circuits,
and other faults.
2. INSPECTING THE ENGINE
made of the fuel pump pressure.
Excessive fuel
pump pressure causes engine to flood
resulting
in poor fuel economy. Low pump pressure
is as
sociated with a lean mixture and
poor performance.
4. INSPECTING THE CARBURETOR
Make a preliminary inspection of
the carbu
retor after first removing the air
cleaner. Check
the position of the choke plate
with the engine run
ning. Throttle the engine down to
idle, then com
pletely close both idle adjusting
needles. If the
engine continues to run for even
a short interval
after this is done, it usually indicates
one or two
faults. The tips or seats of the
idle adjusting
needles may be damaged, or idle
speed set too
high, or else there are deposits
of carbon in the
throttle bores near the throttle
plates.
After a check has been made of the
vehicle,
examine the engine. Check or set
the following
in accordance with manufacturer's
specifications:
distributor breaker points, spark
plug gap, igni
tion timing, condenser capacity,
valve settings,
intake manifold for leaks, compression,
gaskets,
carburetor body and flange screws,
and inlet fuel
pressure.
3. INSPECTING THE FUEL SYSTEM
The fuel system should also be inspected.
Examine all fuel lines for collasped
sections and
other damage. Make a manual check
of fuel line
connections for looseness or leakage.
Check the
fuel tank vent for possible obstructions.
Even a
partially-clogged vent may cause
the engine to
cut out after a f ew minutes of
high- speed operation.
Clean the fuel pump sediment chamber
and the fuel
filter, if there is one. Using
a vacuum gage, check
the fuel pump for air leaks. Connect
the gage to
the line leading to the pump.
A vacuum reading
less than normal at the idle indicates
an air leak
or a faulty fuel pump. A careful
check should be
To continue with the carburetor
inspection,
stop the engine and check the tightness
of the
carburetor to manifold, and manifold
to engine
connections. Inspect all carburetor
connections
and linkages. Examine the accelerating
pump link
to insure that it is correctly
positioned.
If by now the trouble has not been
located, re
move the carburetor from the engine
and dis
assemble. Thoroughly clean and
inspect each part,
using the procedure laid down in
the Service
Manual. The accompanying troubleshooting
chart
lists specific carburetor complaints
and discusses
the various parts which may be
at fault. A rigor
ous cleaning and inspection, coupled
with the re
placement of faulty parts and care
in reassembly,
should prevent recurrence of the
complaint.
NOTE
Many performance complaints attributed
to
the carburetor may be the result
of poor
driving habits, topography and/or
weather
conditions.
